102 HARSHBERGER— COMPARATIVE LEAF STRUCTURE [April 24, 



caprcc, Cakilc ccqnalis, Borrichia arhorcsccns (smooth leaf), Croton 

 maritim-us. 



Two or Three Epidermal Layers. — Euphorbia huxifolia, Nerium 

 oleander, Conocarpus ercctiis (thick leaf), Croton maritimus, Tour- 

 nefortia gnaphalodes. 



Two or More Rows of Palisade Cells. — Passiflora subcrosa, 

 Dodoncca viscosa, Nerium oleander, Sesuviuni portulacastrmn, Cakile 

 ccqnalis, Conocarpus erectus (thin leaf and thick leaf), Scccvola 

 Plmnieri, Borrichia arborescens (smooth and hairy leaves). 



Stomata Depressed. — Sisyrinchium bermudianuni Heliotropium 

 curassavicum, Sesu^mim portnlacastruni, Ipomcca pes-caprcc, Cakile 

 ccqnalis, Conocarpus erectus (thick leaf), Scccvola Plumieri, Borri- 

 chia arborescens (smooth leaf). 



Stomata in Pits. — Lantana involncrata, Nerium oleander. 



Succulent Leaf. — Sesmnuni portulacastrmn, Cakile ccqnalis, Con- 

 ocarpus erectus (thick leaf), Scccvola Plumieri, Borrichia arbor- 

 escens (smooth leaf). 



Hairy Leaf. — Lantana involncrata, Nerium oleander, Borrichia 

 arborescens (hairy leaf), Croton maritimus, Tournefortia gnapha^ 

 lodes. 



Varnished Leaf. — Dodoncca viscosa. 



Leaf Becoming Erect in Sun Position. — Canavolia obtnsifolia, 

 Sisyrinchium bermudianuni, Stcnotaphrum americanum, Ipom<ra pes- 

 caprcc. 



Overlapping Leaves. — Euphorbia buxifolia, Sisyrinchium bermu- 

 dianum, Stcnotaphrum americanum. 



Latex Tissue. — Euphorbia buxifolia. 



Gum-Resin. — Conocarpus erectus. 



Crystals. — Passiflora subcrosa, Croton maritimus. 



Diphotophyll. — Passiflora subcrosa, Canavalia obtusifoUa, Eu- 

 phorbia buxifolia, Lantana involucrata, Nerium oleander = 5. 



Diplophyll. — Dodoncca viscosa, Sesuvium portulacastrum, Ipomcca 

 pes-caprcc, Cakile ccqnalis, Conocarpus erectus (thin leaf), Scccvola 

 Plumieri,'^ Borrichia arborescens (smooth and hairy leaves), Croton 

 maritinins, Tournefortia gnaphalodes = g. 



' Scccvola Plumieri and Tournefortia gnaphalodes are given twice, because 

 it is difficult to decide whether their leaves are diplophyll, or staurophyll. 



